<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .active {
            color: red;
        }
    </style>
</head>

<body>
    <div id="app"></div>

    <template id="my-app">
        <!-- 数组语法 -->
        <h2 :class="['active', title]">{{ message }}</h2>
        <!-- 三元运算符 -->
        <h2 :class="['active', title, isActive ? 'active' : '']">{{ message }}</h2>
        <!-- 数组语法中可以嵌套对象语法 -->
        <h2 :class="['active', title, { 'active': isActive }]">{{ message }}</h2>
    </template> 

    <script src="../js/vue.js"></script>

    <script>
        const App = {
            template: "#my-app",
            data() {
                return {
                    message: "Hello World",
                    title: 'cba',
                    isActive: true
                }
            },
            methods: {

            }
        }

        Vue.createApp(App).mount("#app");
    </script>
</body>

</html>